Melusine
by ChronicallyChill
Summary: He wasn't supposed to be in there. It was the one room he wasn't allowed to enter but he did. And inside that room...inside that room lay a pool of water with a creature that wasn't supposed to exist either. A Shape of Water inspired AU


**Day's Notes:** _Hello everyone! This was a Shape of Water AU request given to me through Tumblr that I'm fortunate enough to have finally finished. It's funny, I actually started writing this and I plot it out months before I actually watched the movie. In fact I just watched it last week. So this is more inspired by Shape of Water, not so much an exact AU. I hope you still enjoy it!_

 **Disclaimer** _ **:**_ **This story will utilize characters and situations that are the copyright of Masashi Kishimoto, Shueisha, Shonen Jump, and Viz Media. This story will also take elements of Guillermo del Toro's Shape of Water. ChronicallyChill is in no way associated with the creator or producers of Naruto or Shape of Water and no copyright infringement is intended. Obviously this is a fanfic meant solely for the entertainment of the fanfic author and (hopefully) it's readers.**

* * *

He wasn't supposed to be in there.

He was told by Orochimaru and his assistant Karin Uzumaki that out of all the rooms in the base, he wasn't supposed to go into that _one_ room. Sasuke had heard the instruction and made sure never to enter The Room as he made his rounds but there was a sound coming from inside of it.

A sound that was suspicious. And was it not his job as security to investigate suspicious noises?

In his defense, his employer should not have granted him access to said room by way of the skeleton key Sasuke used for all of the other doors in the base. It was a foolish mistake but Sasuke wasn't going to bring that up to Orochimaru. Especially not after what he found in The Room.

It was a girl. But at the same time it wasn't. With slow, hesitant steps Sasuke approached the large basin in the center of the room. It was a tank that appeared to be built into the ground and in it was a girl but also not a girl.

Decidedly feminine features━attractive feminine features━ were set in a wary glare. The closer Sasuke got to the tank, the further back the being swam.

Sasuke had many questions but was unsure if the creature would understand him. The pink tendrils that gave the appearance of having hair and the fins off of the side of its throat made it quite clear that he wasn't looking at a human.

As pretty as it may be, it was definitely not human.

Jade eyes narrowed at him with distrust when he reached the edge of the tank.

Sasuke knew that Orochimaru was a sketchy individual. He was always giving half answers or vague responses to what it was that was researched in his lab. It was the kind of behavior that would make a normal person wary but a job was a job.

And Sasuke needed the job. But he wasn't so sure that his desperation for one was worth it anymore.

As curious as he was, there was a job he needed to do and this one required of him to forget what he just saw and to leave the forbidden room.

There was a weak high pitched cry as he closed the door and locked it up again. It gave him pause but he walked away, like he should have done instead of entering.

* * *

He found himself in The Room again the next night.

Sasuke had done his rounds and on his short break he decided to pay a visit to the creature.

Sasuke dragged a chair from a desk in the corner and sat in front of the tank━just far enough that he nor the creature could reach each other.

Pulling out his sack lunch, Sasuke munched on his food observing the creature as it swam around it's tank, peering over its shoulder at him.

The creature never made a sound. It made him think he had only imagined the soft cry from the other night.

Despite never making any noise it was quite easy to tell what the creature was thinking. Big jade eyes were so expressive. They narrowed whenever he caught her eye but whenever he caught her off guard by watching her from his peripheral her eyes widened in wonder in his direction.

Sasuke pulled out a bag of cherry tomatoes and popped one in his mouth. Looking back toward the tank he was startled to find the creature had swam to the side where he was sitting. Her eyes had widened and her head had cocked to the side as she watched the clear baggie holding his snack.

Pulling out a single fruit Sasuke edged closer with hesitant steps. The creature backed away from the edge of the tank as she watched him approach. Sasuke extended his arm, holding the tomato as far from himself as possible.

The creature narrowed her eyes at him, untrusting.

"It's food. See."

Sasuke popped the cherry tomato into his mouth and ate it. He almost opened his mouth to show her that it was gone before realizing that the action was silly. If she wanted it she would take it but he wasn't going to try and coerce her.

Once more, Sasuke pulled out a tomato and extended it to her. One final chance to take one if she wanted to.

A thin, pale arm lifted up from the water. The skin was smooth, no scales like he thought there might be. The creature plucked the tomato from his fingers.

 _Ah_ , Sasuke thought as the creature gently placed the fruit into her mouth. _Webbing between the fingers_.

* * *

No matter how often he came, she still didn't talk. But that didn't stop Sasuke from talking to her.

It had been a long time since Sasuke had anyone he was willing to talk to. Sometimes he wondered if he would eventually lose his voice from the disuse. He had lost his parents when he was younger and then his older brother to cancer before he had graduated from high school. He told this all to her. About how he was all alone now.

"I do have this one friend. We met during basic training and then we were deployed at the same time."

Sasuke tilted his head back so it rested against the tank. He no longer sat in a chair at a safe distance.

"He can eat his weight in ramen in one sitting. It's disgusting."

Sasuke turned his head to look at the creature and wrinkled his nose. She mirrored his action and then smiled. His mouth quirked upwards at the corners but then he frowned.

"We meet up every now and then and people say we're best friends and I guess they're right. Too bad the only thing we seem to have in common is the army. There's not much to talk about except for reporting to each other what our lives are like now that we're back home. Sometimes I think that if we hadn't enlisted we would never have become friends if we had met anywhere else."

He was always trying to tell him what was best for him. Sasuke was tired of hearing what his friend had to say about what he should be doing with his life.

"I'm taking a break from school. A long break. Okay, I dropped out." It was easy to tell himself the truth when someone else was listening. "That's actually why I enlisted. To get help with college payments. But now that I'm back all I want is to fix up Mom's place."

Sasuke's favorite place in the world was his family's lakehouse. Itachi had spoke of going back and fixing it up one day after Sasuke was done with school and they had the money for it. It was the only thing he had left of his family and Sasuke refused to sell it.

"It's a pretty place. It will look really nice once I'm done with it."

 _And you will never see it_.

* * *

Sometimes Sasuke thought he was going crazy. Why was he talking to a creature in a tank? Why was he bringing it sweets?

"I'm not sure if you're even supposed to be eating stuff like this."

The creature smiled coyly at him before snatching the candy from his hand. Once she ate it she stuck her hand out for more. Sasuke sighed and dug out another piece of caramel from his pocket.

* * *

"I sometimes wonder what they call you," Sasuke muttered as he watched the creature twirl in her tank. She laid on her back and flashed glimpses of her form above the water before dipping back below the surface.

She was always doing things like that now that she was comfortable with his presence. He would enter the room and catch her in the middle of grooming, combing webbed fingers through her tendrils tossed over one pale shoulder before giving him a demure smile.

He would have found her behavior flirtatious in a human. With her he was sure she was just fishing for a treat.

Sasuke was about to head back to his duties when he heard a gurgling sound and then a small chirp.

"Sakura."

Eyes widening in shock, Sasuke turned back to the tank. The creature was staring straight at him.

"Karin teach Sakura," she spoke in a warbly voice. "Karin name Sakura. Karin friend."

 _Friends don't stick you in a tank_ , Sasuke wanted to say. He wanted to, but he held his tongue. He held his tongue and selfishly thought only of himself and his position.

"Have you," Sasuke swallowed, "told Karin about me?"

Sakura shook her head.

"Sakura tell Karin, Sasuke leave. Sasuke no come back."

 _Smart. Probably knows that she won't be getting anymore candy if they get rid of me_.

* * *

Now that she was learning to speak their language it was Sasuke's turn to listen.

"Karin nice. Karin say Sakura smart. That Sakura pretty."

Sakura spoke like a child. She understood conversation quite well but her speech was still poor. She strung words together and he understood what she was trying to say but he hoped she would improve. Hoped she would talk more.

He really liked her voice.

"Karin smells nice. Karin say it is perfume. Made of flowers. Sakura like Karin."

 _Does Sakura like Sasuke?_ He caught himself thinking. The back of Sasuke's neck heated up in embarrassment. How mortifying that would have been if he had said it out loud.

"Sakura miss home."

Sasuke was pulled out of his self berating at the sadness in Sakura's voice. He was visiting her in the lab so often now that he shouldn't have forgotten that she had to have come from somewhere else but he had.

"But home no have Sasuke."

Sakura's fingers ghosted over Sasuke's forearm. The barely there touch caused a shiver to run down Sasuke's spine.

He stood up quickly and backed away from the tank. Sakura blinked up at him with her big jade eyes, cocking her head to one side in confusion.

Sasuke cleared his throat and muttered that he had to go back to work.

* * *

The next few times Sasuke came back he kept his distance. He still brought her treats but he didn't stick as closely to Sakura's tank as he used to. And she noticed.

After the fourth day of his new behavior Sakura refused the caramel candy she had grown fond of and stuck to the far side of her tank.

"What's up with you?" Sasuke's eyebrows pulled forward in a deep frown.

"Sakura not pet," was her reply. "No want stupid candy."

"You sure did like them before," Sasuke muttered. "Always acting cute to get a piece."

"Sasuke give candy. Sakura thought Sasuke like Sakura."

"That's not━I mean, you're━"

"Sakura know what Sakura is." Sakura gave him a weak smile. "Sasuke leave now. Want to be alone."

"Sakura━"

Sakura dove under water, down where he couldn't follow.

* * *

Sasuke returned every night and she would dive under the surface, refusing to speak to him.

 _What a stubborn little thing_.

"What was that?" Naruto, Sasuke's army friend, quirked an eyebrow at him.

"Nothing," Sasuke sighed.

He had hoped on his night off that going to the bar would distract him from his problem with Sakura but nothing had. In fact, Sakura was distracting him from having a good time out with his friend and the small, mousey girl Naruto had excitedly invited to introduce to Sasuke.

So caught up with thinking of Sakura, Sasuke kept forgetting the girl's name. Not wanting to ask it so far into the night he stuck to calling her "the Future Mrs. Uzumaki" which caused her to blush furiously and Naruto to tell him to quit teasing him.

"So how is working with my cousin? Is she a pain?"

"I don't really work with her now do I?" Sasuke rolled his eyes. Naruto had been the one to tell him about the job offer but he was sure Naruto had no idea what it was that his cousin Karin did for work. "I never see her."

Karin worked during the day mostly and he never saw the redhead except for when she was heading home for the night.

"Weird. I could have sworn she insisted on you applying because she had the hots for you." Naruto took another swig of his beer. "She sure sounded interested when I told her about how you wanted to fix up that house at your family's lake."

"Maybe she thought I had money," Sasuke snorted. Typical. There was no money. Just property that had stayed in his family for generations. The house had been a gift to his mother from his father. They had passed away before it could be completed unfortunately.

" _Karin teach Sakura. Karin name Sakura. Karin friend."_

"She's a bit of a pain sometimes but I doubt Karin's that shallow," Naruto defended his cousin.

"Me too. I doubt she is."

* * *

"Stop!" Sakura narrowed her eyes at Sasuke, throwing the caramel wrappers he had dropped into her tank onto the floor. "No trash where Sakura sleep!"

"I'm sorry."

"Why Sasuke throw trash then?"

"I'm not apologizing for that."

Sakura narrowed her eyes even more.

"Okay, I'm sorry for throwing trash into your tank." Sasuke rolled his eyes. "But I'm talking about the other night."

Sakura sank lower into the water so that only her eyes were above the surface. Her eyes were narrowed as she continued to watch him, wary.

"It's weird when I don't talk to you. When you don't talk to me."

Sasuke sat by the edge of her tank. He rest his elbow on the rim and propped his head up by laying his chin on his fist. After observing his relaxed state, Sakura relaxed as well and flipped on her back, drifting along the surface.

Sasuke's neck started to heat up as he watched her drift lazily, her pale smooth body on display.

"What am I going to do with you?" He sighed. Sakura just smiled at him and twirled, giving him flashes of her pale skin.

* * *

Things were back to normal. Or as normal as being friends with an amphibious humanoid being was.

Sakura didn't try to touch him again. It seemed that after the first attempt was rejected she had decided to keep a comfortable distance between them. She got close enough to talk and to grab whatever treat he had brought her but she wouldn't reach out to him.

And it disturbed him how he hoped she would try again.

"That's new."

Sasuke poked Sakura's forehead right on the new rhombus shaped marking. He had noticed a slight coloration change from time to time but it wasn't until now that the marking had taken a form. It drew more attention to her face and the brightness of her jade eyes.

 _Like she needed to be any prettier._

Sighing, Sasuke leaned back against the tank and pulled out his dinner. He unshelled a hard boiled egg and laid it on the edge of the tank with some cherry tomatoes from his salad.

He and Sakura ate in companionable silence. He didn't know what Sakura was or what she was doing here but he enjoyed her company. He enjoyed talking to her and watching her swim in her tank and listening to her warbly voice.

 _Too bad she's not human._

It was unnerving how often he had to remind himself of that fact. Had to remind himself that he should care that she wasn't human like he was.

To distract himself he started to whistle a tune. When he was younger his mother use to play on a baby grand piano when it was quiet time at home. The melody she played would get stuck in his head and he would catch himself whistling when he was lost in his thoughts. It helped calm his thoughts.

From somewhere far away, he could hear the splashing of water. Could hear the dripping of water approaching him but it wasn't until a drop of water fell on the tip of his nose that he snapped out of his thoughts.

Before him stood a pair of bare opalescent legs with purple markings. His eyes followed them up to rounded hips and a smooth lower abdomen. Before he could open his mouth to say anything, Sakura dropped right into his lap.

Lips parted and wide jade eyes staring at him in wonder, Sakura slid a webbed hand up his chest and wrapped it around his neck, soaking his clothes.

 _She's not human._

Sakura pressed her body closer, her tendrils falling over her shoulder onto him. She shifted in his lap, pressing his crotch to a body part he had assumed she didn't have. Or what he didn't want to think too much about.

 _She's not human._

"Sasuke…" Sakura's warbly voice was right by his ear.

 _Not human…_

Sasuke's breath hitched when Sakura's cool palm slid under his shirt. She growled low when she tried to pull her hand out from underneath and got caught in the fabric. She turned her palm around and clawed at the fabric, ripping the buttons from his shirt to free herself.

Sakura cocked her head to the side, gazing with wonder at the flexing of Sasuke's abdominal muscles as he tensed up at her scrutiny.

"Sasuke different," she murmured. "Different from Sakura."

"Yeah." Sasuke swallowed the lump in his throat. "We're different."

"Sakura no care. Sasuke care?"

Sakura was close enough for Sasuke to see the translucent sort of film over her eye. Another eyelid that most likely protected her when she was underwater. She blinked at him and let out a soft sigh. She slid down his body and lay her head on his chest.

" _Ah_. Dun-dun like Sakura." she slid her webbed fingers until they lay over his heart. She traced them as best as she could on his skin. She skimmed her lips on his chest and murmured, "Just like Sakura."

Sasuke placed his hands on the small of her back. Her skin was wet and soft, delicate to the touch. Sliding his hands around her lithe form, he spread his palm flat on her sternum, feeling her heartbeat against his hand.

"Yeah," he whispered. "Just like Sakura…"

* * *

She was running out of time.

Karin pulled at her hair and then slammed her face into her hands. She screamed into her palms.

After screaming she inhaled deeply and let out a long exhale. Rearranging her glasses on her face she counted out prime numbers until her breathing was back to normal.

She had tried everything she could to get Sasuke's attention, to convince him of selling his lake property to her. She even went as far as taking him out for drinks in the hope that a little flirting would sway him but the answer was always no.

Karin had even stooped so low as to ask her cousin to help her.

Straightening out her desk she left her office and walked down the hall to Sakura's room.

"Hey pretty girl," Karin called out. She knew Sakura would recognize her voice and swim to the surface.

Sure enough, before she could even make it to her cabinets, Sakura's pink external gill filaments broke through the placid surface.

"I gotta check your water's pH balance, sweetie."

As Karin tested the water in the tank she observed Sakura as she swam about.

Her tail had disappeared and her adult markings had fully developed. She was reaching the stage in her life where she was ready for mating and that worried Karin.

Soon she wouldn't be able to stall Orochimaru's plans for the nixie.

Orochimaru let her take the lead in their research but never failed to remind her that _he_ was the one in charge.

Karin didn't need the reminder. She was haunted every day by the face of their first specimen. She couldn't get his sharp tooth smile out of her mind.

Or his vivisected body.

Her orders for the day were to give Sakura a full physical exam. She did it often to make sure she stayed healthy despite the fact they deprived her of a natural body of water. But today was different. Today she had to evaluate her and prep her for artificial insemination.

Karin wanted an in vitro fertilization but Orochimaru insisted on in vivo for the first pregnancy. She held back from sobbing at the implication that they would be forcing Sakura to give them multiple specimens.

Karin had tried to refrain from becoming attached to Sakura. Tried to save herself from more heartbreak after Orochimaru killed her first nixie.

But just like with Suigetsu she just had to go and name Sakura.

This was more than she had ever bargained for when she went into the field of herpetology.

"Reading today?" Sakura swam to the edge of the tank and turned her eyes up at her hopefully. Karin shook her head sadly.

"We have labs to do today, Sakura."

"No." Sakura pouted. It was her least favorite thing.

"Come on. If you're a good girl I'll play some music for a full hour."

Sakura immediately lifted herself to perch on the tank's rim.

Karin's experience with Suigetsu made it easier to handle Sakura. She would occasionally get temperamental but it was easy to placate her.

Although both nixies loved music, what Sakura loved the most was learning. It was easier to teach her how to speak human languages and she yearned to learn how to read the books Karin read to her.

While Karin prepped everything she needed for the required blood work, Sakura started to hum. Karin put down the vial she was holding and stared at her, russet eyes wide in shock.

 _Clair de Lune?_

Karin only ever played pop music, hoping the upbeat tunes would make Sakura happy.

"Karin?"

Karin shook her head and picked up the vial again.

"I need your right arm."

* * *

Angry didn't even begin to describe how Karin felt. She was downright furious. She checked the results again and again.

Sakura was pregnant. She was pregnant and Karin has no explanation for it.

She couldn't ask Orochimaru for he was the one that asked her to prepare Sakura for insemination. There was no way he was responsible and he was the only person that had access to the lab they kept Sakura in.

Karin's head snapped to the tank at the sound of Sakura's humming. Sakura had her arms crossed on the tanks edge. She laid her head on her arms, smiling dreamily.

 _Male frogs sing to attract mates._

Karin folded the lab results and tucked them into her bra.

 _Time to find this "frog."_

* * *

Usually when Sasuke came to work the building was already empty. Karin would occasionally be leaving when he came in but she never stuck around unless she wanted to bug him about something she couldn't wait for Naruto to pass on.

Today she was waiting for him inside of Sakura's room.

"I knew it!" she shrieked, flailing her fists at him, pounding on whatever part of him she could reach.

"Uzumaki, cut it out!" Sasuke grabbed her wrist and pushed her off of him.

"You fucking pervert!" Karin hissed, face flushing red with anger. "How could you do something like that?"

Sasuke swallowed the lump in his throat. He should have expected to get caught. He was expecting it after the first time but after nothing had happened he got comfortable. Too comfortable.

He looked past Karin to where Sakura was sitting at the edge of her tank. She wouldn't look at him, keeping her eyes downcast.

"She's pregnant you jackass."

"What?" Sasuke turned his attention back to Karin.

"Apparently nixies are able to mate and crossbreed with humans." Karin crossed her arms in front of her chest. "That wasn't something I intended on experimenting on ever but your indiscretion has left me no choice but to follow through. Especially since she won't let me get rid of it. If I try to bring up the topic she threatens to poison me."

"Poison?"

"You fucked her without even thinking about the consequences?" Karin wrinkled her nose in disgust.

Sasuke shot her glare and she rolled her eyes before explaining.

"When threatened, a female nixie can secrete poison through their skin. She almost got Orochimaru good when he brought her. I also say female because our deceased male didn't seem to have the same capabilities just a sharp set of teeth like a shark though he was monophyodont. He obviously didn't have the glands that produced them."

"There was another of her kind?"

It was shocking enough that Sakura existed in the first place but to find out that there was potentially more like her was on a completely different level.

"We learned all we could from the male while he was alive so Orochimaru…" Karin closed her eyes and exhaled a shaky breath. "He ordered an autopsy."

"He's not killing her," Sasuke growled marching over to the Sakura's tank. Startled by the quick movement Sakura fell back into her tank.

"I wasn't planning on letting him. And that's not his plan for her. At least..." Karin swallowed the lump in her throat. "At least not yet."

"So what was your plan?" Sasuke didn't look up at her. He kept his eye on Sakura who was curled inward into herself below the surface.

"I was going to try and stall his plans and figure it out before she supplied him with enough specimens for him to decide it was time for an autopsy on a female specimen."

Karin took a seat by Sasuke by the edge of the tank. She grabbed his shoulder to get his attention.

"I was supposed to get you to sell your property to me. It's a decent sized open lake and because it's private property there would be less chance of someone seeing her. I can't keep her in a tank her whole life. It's like asking you to live in a bathtub."

Sasuke stared at her a moment, face blank, before turning his attention back to Sakura.

"I know you won't sell me something that means so much to you but it's obvious you care about her. At least enough for me to trust you with her if anything were to happen to _me_."

Sasuke's brows furrowed. He gave her a questioning stare, imploring her to explain.

"I can't just take her. Orochimaru will come after me. Or you if he thinks you have anything to do with it."

Karin pulled a vial out of her pocket. The liquid inside was a sickly green color.

"This is nixie poison supplied by Sakura."

Karin tucked it back in her pocket, out of sight.

"I'm going to use it on Orochimaru and then burn the lab down, make it look like an accident. The only person that would care is his assistant Kabuto that works in one of his labs abroad. Considering we do a lot of illegal work I don't think he will come after me as long as he gets the money he's due."

"And what are you going to do with Sakura?"

Sasuke didn't have to ask, he knew he had something to do with her plans. She may have tried to find a way to use him without his knowledge before but now there was no avoiding it. Sasuke was involved whether she liked it or not.

"I need you to be ready to receive her on your next off day. I'm going to make it as easy as possible for you but it's a huge risk. Nixies are bound to the body of water they call their home. They can come on land but that's usually to mate according to the male specimen. They can't stray too far. I'm hoping that she can make the journey to your lake."

Karin gripped the front of Sasuke's shirt and pulled him down so they were eye to eye.

"We may lose her in the transfer," Karin whispered harshly. "But it's a gamble I'm willing to take. Don't fuck this up."

* * *

As soon as he heard the back doors to Karin's van open up, Sasuke reached out to pull the crate she was sliding in with the assistance of one of her stainless steel mobile tables. Sakura's voice was muffled through the wooden planks but it was obvious she was upset. Sasuke reached for the latch on the lid but Karin slapped his hand away.

"Don't open it!" Karin snapped. "Do not open this crate until we're within the lake's perimeter."

Karin drove as if she were going home before she made a detour to leave the city.

When Karin merged onto the highway and picked up speed, Sakura started banging her fist on the walls of the crate.

"Talk to her," Karin ordered. Sasuke raised a brow at the tone of her voice. "It will soothe her."

Leaning over the crate, Sasuke murmured soothing words, trying his best to ignore the fact that Karin could hear everything.

It was hard to do considering she would snort every now and then.

They drove for two hours, only another half hour until they were within the Uchiha property line, when Sakura stopped making any noise from within her crate.

"Sakura?" Sasuke panicked when she stopped responding. "Sakura!"

Without caring about Karin's earlier warning, Sasuke yanked the top of the crate off.

The inside of the crate was lined with a plastic tarp, allowing for Sakura to lay in water from her tank.

Sakura's chest was rising and falling rapidly and her eyes were glazed over.

"Karin!"

"Check her temperature!"

"She's warm. Really, really warm."

Karin stepped hard on the gas pedal, picking up even more speed.

"The crate must have trapped her in heat. Fuck!"

Making a sharp turn, the water in the crate jostled around and Karin chanted out a stream of curses.

The van's A/C was already on the highest setting possible. There was no way to make the van any colder.

Karin headed straight to the beach and backed up so they could slide Sakura out using the tarp.

Sasuke didn't wait for her. As soon as she parked the van he lifted Sakura into his arms and headed straight for the lake.

"She needs to be acclimated to the lake's temperature and I need to check the pH. She could go into shock!"

There wasn't enough time for all of that. Sasuke ran straight into water, fully clothed and submerged himself and Sakura underwater. He stayed under until he felt Sakura twitching in his arms. A few jolts and she shook herself from his hold. As she swam away Sasuke broke through the surface in desperate need of oxygen.

Gasping for air, Sasuke looked around frantically for any sign of Sakura. After a moment of he stood still, watching as the surface of the lake remained completely still.

"Where did she go?" He asked Karin who was standing on the shore, her boots in her hand.

"This is the biggest source of water she's ever known." Karin sat on the beach and pulled her knees up to her chest. "It's a new experience. I hope she doesn't get overwhelmed."

"So what to do we do now?" Sasuke asked looking back at the placid surface of the lake.

"We wait."

* * *

Karin had to go back to Orochimaru's facility. Sasuke always wondered what happened on his off days. It turned out that those were the nights that nocturnal research needed to be taken care of.

Karin had explained that for weeks she couldn't figure out what had caused the change in her observations of Sakura's behavior. She was really kicking herself over not having put two and two together earlier.

She said she could easily explain her absence during the day because she was always going out to different wetlands to procure specimens for other experiments but at night she had to go back to her lab.

She also had to get ready to destroy the lab to get rid of Orochimaru and so it would be as if Sakura never existed.

Sasuke didn't want to leave the lake just in case Sakura came back. He only went into his house after two hours to open the windows and check that the plumbing was working since he had called the water company the morning after Karin told him her plan. Turning on the heat was easy considering the house used heating oil. Sasuke had stocked up the previous summer and shut it off for when he wasn't doing any work in the house.

It was nearing the end of winter and nights were chilly. Sasuke grabbed one of the quilted blankets from the linen closet and dusted it before heading back out the lake.

He chose to sit by a tree that sat on the edge of the lake just a bit away from the sandy beach. When he was younger his brother always talked about tying a rope swing to the tree so they could swing into the lake. His mother immediately put an end to those plans by pointing out how shallow the water was in that location. His father promised to build them a proper dock so that they could go fishing.

The lake and an unfinished house was all he had left of them.

And now even Sakura was gone.

* * *

He woke up thinking that it had started raining.

He didn't plan on sleeping outside but he dozed off while waiting for Sakura. The lake was large but there was a chance she had found the river and traveled beyond the boundaries of the Uchiha property.

Sasuke opened his eyes as water continued to fall on him in drops. The first thing he saw were a pair of slim pale legs.

"Sakura?"

She dropped in his lap, nuzzling her face against his chest.

"Sakura like it here."

"Where did you go?"

"Needed to see if safe."

Sakura pulled back and placed her hands on her lower abdomen. Her stomach had already begun to round out.

"Karin was mad."

"Yeah, but not at you." Sasuke cupped the side of her face. "She was mad at me."

Sasuke drew her close and pressed his lips against hers. Sakura stiffened in his hold and then pulled away from him.

"Sakura already with child." She put his hands on her abdomen. "See?"

"No that's━I mean, yeah you are but…" Sasuke sighed and hung his head. "Humans don't just have sex to procreate. Don't worry about it."

"Can mate when already with child?"

"Karin didn't teach you much did she?"

Sakura shook her head. Considering what she had explained to Sasuke it was no wonder Sakura only knew what her instincts told her.

Sasuke contemplated explaining any further without Karin present when he felt Sakura tug on his shirt sleeve.

"Hm?"

"Sasuke stay with Sakura?" She turned her head to the lake.

"I can't breathe underwater like you can. I can't live in the lake."

Sakura's shoulders drooped. Almost instantly she straightened up, her face set in a scowl. She bared her teeth at him, flashing her sharp canines.

"Sasuke always leave Sakura."

She stood up fast, yanking herself out of Sasuke's hold.

"Wait!"

Sasuke stood up and grabbed hold of her arm before she could dive back into the lake.

"Listen to everything before you go running off again. Annoying," he huffed under his breath.

Sakura crossed her arms over her chest and tossed her tendrils back in a perfect imitation of Karin when she was angry with someone.

"I can't live in the lake." He tugged gently on her arm and led her up the gentle slope to the house standing on top of the hill. "But I'll be living there. And you can come be with me and I can come visit you. Even during the day."

Sakura's lips parted and her eyes shimmered in awe.

"Close!"

"There's not much inside yet but do you want to go see it?"

Sakura nodded, pulling on his arm. Sasuke chuckled softly and scooped her up in his arms. She chirped with glee at the sudden motion. He only meant to carry her for her comfort as her elongated and webbed feet would have more difficulty climbing the slope than he did but her enjoyment was a bonus.

"I'm going to bring more furniture later," Sasuke explained unnecessarily. It was more himself gathering his thoughts that informing Sakura. She was too dazed by the inside of the house to pay attention to him. "Luckily the idiot and his girlfriend were able to help me bring my truck here earlier this week."

He set her down on his mother's old rocking chair and watched as her eyes went wide when the chair rocked back and forth. She grabbed on tight to the arms of the chair, scared that she would fall off.

Sasuke smirked at her before lightly pushing the chair so it would continue rocking. She squealed but when she realized that Sasuke was supporting her, she settled into the chair only lightly gripping the arms.

"Karin never told me how long you could be out of the water," Sasuke sighed. As great as it was to be spending time with her, he knew she had to go back to the lake. It was where she belonged.

"Sakura fine here." Sakura turned her head away haughtily and crossed her arms in front of her chest.

Sasuke just shook his head and lifted her out of the chair. He wouldn't have brought her into the house if he knew she was going to refuse to go back to her proper habitat.

"She's going to call us as soon as she can and then I'll know what's best for you. But for now you gotta go back."

Sakura wrapped her arms around his shoulders and held on tight, pressing her face into the crook of his neck.

They were separating again, just like they did every day. But at least they knew they would have a tomorrow which was something that wasn't assured in the lab.

* * *

" _Congratulations, you're unemployed."_

Sasuke rolled his eyes even though Karin wouldn't be able to see him do it. He had tried to keep busy spending time with Sakura and cleaning the house but it didn't do anything to help his irritation with the redhead. It was approaching late evening by the time she got in contact with him.

" _I'll be taking care of some stuff over here but I should be able to head over to the lake in about two weeks. How's my girl doing?"_

"She's enjoying her freedom." Sasuke sighed and laid back on the sofa he was shoving under the bay window before the call. "She brought me a catfish. Well, half of a catfish. She wasn't happy that I wouldn't eat it so I had to have a discussion about cooking with her."

" _Don't turn down her gifts. She was doing something really nice for you."_

"I'd like to see you eat a raw catfish."

" _Hey, I'm not her mate."_ Sasuke's neck heated up at the term. " _You should be more understanding and caring."_

"You just want to use me as your guinea pig to find out how nixies interact in pairs."

" _I actually don't think they interact much outside of the actual act of mating. The male nixie Orochimaru captured was violent and preferred isolation. And although Sakura is a sweetheart she showed signs of having only interacted with other females of her species. It took a long time to get her to trust me due to being forced into a tank but Orochimaru couldn't get anywhere near her without her showing signs of hostility. I think the females are gentle beings that probably care for their young but that males break off and only seek out their own kind when it is time to mate. It's probably an anomaly that she is so attached to you, her mate."_

"That explains a lot."

It was probably the reason why she rejected affection the previous night. She probably thought he wouldn't want to engage in any acts that resembled mating now that she was pregnant.

" _Explains what?"_

"Nothing you need to know about." Like hell he was going to talk to her about his sex life. "So what do we do now?"

" _Keep track of her pregnancy until I can get there. I need to settle some things but it looks like I did a pretty damn good job with the lab."_

"Congratulations, you're a professional arsonist."

" _Shut up."_

* * *

It took two months but Sasuke had finally finished up the remodel on the master bedroom.

He had left it last on purpose having originally thought he could sleep in one of the other bedrooms but Karin had taken over both. She used one as her bedroom and converted the other one into a small lab where she continued her research on Sakura.

It was never Karin's intentions to reveal her findings to the world. She had explained that she had worked with Orochimaru because he was the only expert in herpetology that could assist her in fulfilling her personal ambition of finding proof that the being she saw as a little girl in the river before she blacked out truly existed and that it has saved her from drowning.

Her experience with Sakura proved that it could be no other creature but the one Orochimaru had dubbed a nixie after the water sprites in European folklore.

After the tedious task of settling all of her accounts she packed up all her stuff and moved in with Sasuke where she acted like a mother-in-law that had no sense of boundaries.

"Where do you even get this stuff?" Sasuke wrinkled his nose at Karin's ultrasound equipment. They had an argument the previous month about the cost of their electricity bill but she kept insisting they could find enough for it in their budget planning.

Sasuke found the funds in Karin's pockets which she wasn't too happy about but she couldn't argue considering he didn't charge her rent. It had really helped her case that she was the only person qualified to give him any assistance with Sakura.

"It's none of your concern," Karin snapped. "Now go get Sakura. I'm sure she's due any day now."

Sasuke ignored the fact that she was ordering him around and marched down to the tree near the shallow part of the lake.

Now that Sakura was nearing the end of her pregnancy she wasn't swimming out to the deeper parts of the lake. She had made herself a cozy little patch of mud and reeds to lay in as she waited for the birth of her child.

A high pitched cry broke through the tranquil atmosphere.

"Ka━" Sasuke began to call for help when a red blur ran past him.

"Don't just stand there!" Karin barked, moving faster than he had ever seen her move.

* * *

Naruto hated how far Sasuke had moved away. It was difficult to get him to come around to hang out when they were in the same city and now that he was off in the country he saw him even less.

After the building Sasuke worked security for burned down, he packed his bags and moved into his family's lakehouse. He found a job at a hardware store in nearby town and settled down for a quiet life in the country.

"I need to use the restroom," he told his fiancée.

They pulled up at a combination gas station and convenience store in the town Sasuke now lived in. Most of the populace of said town lived a half hour drive from the lake Sasuke owned.

Naruto had wanted to make his announcement in person which he knew Sasuke would find annoying considering he could have just called him but he missed his best friend.

After finishing up his business, Naruto strolled the aisles of the convenience store. He was sure Sasuke wouldn't have ramen stocked at his house and Hinata was probably craving something sweet. He knew that if he didn't bring his cousin some chocolate she was likely to punch him in his arm.

When Naruto had first heard that his cousin was going to be living with Sasuke he was disturbed. He didn't want them to be hooking up but when he brought it up to Karin she started to gag and told him not to be an idiot.

Apparently the Uchiha's lake was the habitat of an endangered amphibious species and Sasuke's home was a convenient place to set up camp so that she wouldn't have to shuffle any work a far distance.

"I'm serious, dude!"

Naruto's ears perked up at the sound of a boy in his late teens. He shifted his attention to the cashier who wasn't taking his excited friend seriously.

"I'm not going to humor you, Haru. Last year you were ranting about a monster sized alligator in the river and now you're talking about a _mermaid_? When are you ever going to quit?"

"I'm not the only who's seen it. Sara swears she saw a smaller one with it too. The big one has pink hair and the smaller one black hair."

"Oh, please." The cashier rolled his eyes. "Shut up, I have a customer."

Naruto smiled at the two boys and paid for his things. In such a small town they were probably starved for any type of entertainment. Shaking his head he got in his car and broke out into the laughter he had tried so hard to hold back inside the store.

"What's so funny?" Hinata asked.

"You're not going to believe the kind of stuff the locals come up with for fun."

* * *

 **Day's Notes:** _this is my longest one-shot. I hope you guys liked it.  
I may one day do a spin-off of this._


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